We are porting DELPHI, a finite difference Poisson-Boltzmann solver developed in the Honig group, to the massively parallel CM-5 supercomputer. The CM-5 data parallel mode is very convenient for implementing the finite difference iterative algorithm in DELPHI and we expect to be able to obtain solutions for proteins on very dense grids in very short CPU times (on the order of seconds for 2563grids).